How to setup SSH keys | How to setup Repo in GitHub and Setup Java Project in GitHub | How to add a Java Web App in GitHub using Maven

GitHub is one of the popular git-based version control systems. GitHub is very good example for Software-as-a-service, hosted on cloud for storing and sharing code. 

We will learn how to create a Java Project using Maven and push Java Project into GitHub from Ec2 instance. Let us learn how to create SSH keys and securely connect to gitHub from EC2 instance. 

Git is a purely distributed version control system. Click here to learn more about Git and its advantages over other SCMs.

Pre-requisites:

1. GitHub account

2. Git client installed

3. Connect to your Jenkins EC2 instance

Step # 1 - Create private repository in GitHub

Go to https://github.com/

Click on New to create a new repo 

Also choose initialize with repository with a README option.

Step # 2 Create SSH keys from your Jenkins EC2 machine

Login to your Jenkins EC2 instance using Git bash. (make sure you are connected to Jenkins instance)

make sure you are connected to EC2 instance by ssh url. 

Type ssh-keygen (and then click on enter four button times, do not give any password). 

ssh-keygen command will generate two keys - public keys and private keys. We need to upload only the public keys into GitHub.

If you already have keys generated, you can use the existing key, you don't have to overwrite the existing key.

copy the content of public key by executing below command in Git bash:
sudo cat ~/.ssh/id_ed25519.pub

Step # 3 - Upload SSH Keys in GitHub

Go to GitHub, click on Settings.

Copy SSH keys Key section and then click on Add SSH key.

Step # 4 - Clone Repo locally

Now click on the Cat icon on your top left to go back to repo you just created.
Click on the repo you created in step # 1, click on Code, under SSH

 

Copy the SSH url and go to your EC2 instance using git bash and perform below command:

git clone <paste the ssh url >

type yes to connect

After you clone, you should see something below:

type below command to list the directory
ls -al
The above command should list the directory you have cloned.

Now go into repo folder(red circled like above) you have cloned.

cd MyApplicationRepo

Step # 5 - Create Java Web App using Maven

use below maven command to create Java Web App using Maven. Maven is the build for creating and building java projects. Click here to know more about Maven.

mvn archetype:generate -DgroupId=com.dept.app -DartifactId=MyWebApp -DarchetypeArtifactId=maven-archetype-webapp -DinteractiveMode=false

Step # 6 - Push Java Web App using Git commands into GitHub

type below command to see the new folder called MyWebApp
ls -al

type  below command to see the newly created project in red color

git status

Now add the newly created folder by executing below command:

git add  *

Now make sure all the files are moved to staging area, when you execute below command:
git status

git config --global user.name "your github user_id"

git config --global user.email "youremailid"

Perform below command to commit the changes to local repository first.

git commit -m "my first project check-in to GitHub"

Now perform below command to push from local repository to remote repository. 

git push

 

Verify code changes in GitHub

Now to GitHub and click on the repo, you will see your commits.

You can also watch the videos of the above lab exercise in my YouTube channel given below: